In recent years, data processing devices, represented herein by mobile telephones, have started to incorporate biometric authentication functions to preserve security and improve usability. For example, a mobile telephone described in Patent Literature 1 stores therein, as biometric information, pieces of fingerprint data pertaining to respective fingers of a user in one-to-one association with different applications (e.g., a camera function and an infrared communication function). According to Patent Literature 1, when the user runs one of his/her fingers over a fingerprint sensor, the mobile telephone compares fingerprint data authenticated by the fingerprint sensor (hereinafter referred to as “authenticated fingerprint data”) with each of the stored pieces of fingerprint data, and activates an application associated with one of the stored pieces of fingerprint data that matches the authenticated fingerprint data.
The above configuration allows the user to easily activate a desired application simply by having a fingerprint authentication sensor authenticate one of his/her fingers that is associated with the desired application, without performing cumbersome operations to activate the desired application.